Doug C
Senior Heliman
Location: Northern CA
My Posts This: Topic Forum | U.S.U.L.
I own a Predator Max 90 with the Wren 54 conversion and I will try to answer some of your questions as they apply to mine.
1) On Wren's website the gearbox output starts from 4300 rpm - is that the idle rpm?
--> that is Turbine RPM, 43,000 not 4,300
I would like to use HD clutch from century predator.
--> that is what it is designed for...
While it is designed for nitro engine which idles at 2000rpm i realize it will engage too early causing the rotor to rotate at turbine idle...
--> works like a champ on mine, at Turbine idle (around 45K rpm) the 2nd stage is not moving the rotor blades, movement starts around 50K Turbine rpm.
2) Is there any other solution to disengage 2-stage turbine output from rotor at idle?
--> NO
3) I would like to build custom frame and mounts for it - can i use second stages's flange as a main support point for mounting it leaving gas turbine hanging unsupported?
--> NO, the turbine must be supported, the weight will snap the 2nd stage.
4) Is it possible to mount it so the gearbox output is facing down instead of up?(i've seen one sph5 mounted like this)
--> YES, according to other threads in this group, it is not a problem for the new version 2nd stage gearbox
5) Is it possible to mount it backward direction(turbine inlet facing tail rotor).
--> yes, the turbine doesn't care which way it is pointing
Can i reverse the exhaust so it would not catch too much air(should i expect problems with this) in FF flight? Is Wren selling straight 90 deg exhaust?
--> would require a custom exhaust setup
6) What is the diameter of threaded gearbox output shaft?
--> 5/16-24, same as the OS .91 family of engines
7) Is Wren 54 gearbox output turning CW or CCW? Possible to reverse?
--> Don't know, never looked, but the 2nd stage turbine wheel is what dictates rotation and that would have to be changed if you wanted to change direction
8) Where can i buy 15mm diameter mainshaft and 3 bladed rotorhead for it?
--> No idea, maybe someone else can answer.
I know vario XLC and rotortech Zealous II uses one, are there any other alternatives?
--> see above |
